St. Ann, MO: what USGS's seismic model says
USGS's ASCE 7-16 seismic design model - the same standard building codes use - places St. Ann in Seismic Design Category D: High seismic hazard - this is the category most of coastal California, the Pacific Northwest, and other active fault regions fall into. Code mandates significant seismic detailing and restricts irregular structural configurations. This is the category the Brace + Bolt scope (cripple-wall bracing, foundation bolting) is built for. That puts St. Ann in the 82th percentile nationally for seismic hazard - higher than 82% of the 4,875 US cities USGS was checked against here.
Where St. Ann sits in Missouri
The raw figures: peak ground acceleration 0.215g, short-period spectral response 0.388g, 1-second spectral response 0.148g. Among 135 Missouri cities in this dataset, St. Ann ranks 44 for seismic hazard, the 68th percentile within the state. About 12,704 people live in St. Ann, Missouri.
Bracing and bolting: the actual cost
Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for Missouri. A typical retrofit still runs $5,000-$10,000 nationally, about $7,000 for a common single-family job.
Insuring against this, not just retrofitting
Outside California, earthquake coverage is typically sold as an endorsement added to a standard homeowners policy, not a separate product - worth asking about directly when getting a home-insurance quote for a St. Ann address.
More on how this number was built
The methodology guide covers exactly how USGS's public design-maps API produced St. Ann's numbers. The guide to what a Seismic Design Category actually means covers why a category is never a substitute for an engineer's assessment of one specific house.